JP2011073279A - Unfoamed sheet, and method for manufacturing foamed decorative sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed decorative sheet excelling in surface strength and having a desired expansion ratio and to provide an unfoamed sheet for obtaining the foamed sheet. <P>SOLUTION: The unfoamed sheet includes a resin layer containing a foaming agent, laminated on a base material. A resin component in the resin layer containing the foaming agent is a polymer obtained as at least one kind of monomer selected from a group comprising acrylic acid and methacrylate, and a tensile modulus of elasticity of the resin layer containing the foaming agent is 100-200 MPa. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an unfoamed sheet and a method for producing a foamed decorative sheet using the sheet.

  Conventionally, foamed decorative sheets (foamed wallpaper) are known in which a foamed resin layer of vinyl chloride resin is formed on a base material (for example, backing paper). In recent years, in consideration of the environment, halogen-free resins such as ethylene-vinyl acetate copolymer resin (EVA), acrylic resin, and olefin resin have been used for the foamed resin layer (Patent Document 1). ~ 3 etc.).

  For example, paint containing a microcapsule-type foaming agent added to an emulsion containing an acrylic resin and ethylene-vinyl acetate copolymer resin, coated on a substrate, dried, printed with a pattern on the surface, and then heated and foamed A foamed decorative sheet formed by forming an uneven pattern with an embossed plate is known. In addition, an unfoamed resin layer made of a resin composition obtained by adding a thermally decomposable foaming agent to an ethylene-vinyl acetate copolymer resin is formed on a substrate by melt molding, and then a pattern layer is printed on the surface. Next, a foamed decorative sheet is known which is heated and foamed to form an uneven pattern with an embossed plate.

Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A

  By the way, in the conventional olefin-type decorative sheet, since the surface strength is weak, the reinforcement is needed. As the method, for example, 1) a method of keeping the foaming ratio of the foamed resin layer low, and 2) a method of providing a film layer or a thick coating film on the foamed resin layer have been proposed.

  However, in the method 1), it is not possible to conceal the unevenness of the foundation when the decorative sheet is applied. In addition, the method 2) has a problem that the decorative sheet itself is hard, so that wrinkles and curls are likely to occur.

  Accordingly, the main object of the present invention is to provide a foamed decorative sheet that has these disadvantages improved, has excellent surface strength, and has a desired expansion ratio, and an unfoamed sheet for obtaining the foamed sheet. The main purpose is to provide it.

  As a result of intensive studies, the inventor of the present invention has formed a foamed decorative sheet by foaming an unfoamed sheet obtained by laminating a foaming agent-containing resin layer on a substrate. The inventors have found that the above-mentioned object can be achieved by foaming when is within a specific range, and have completed the present invention.

That is, the present invention relates to the following unfoamed sheet and a method for producing a foamed decorative sheet using the sheet.
1. An unfoamed sheet obtained by laminating a foaming agent-containing resin layer on a substrate,
The resin component of the foaming agent-containing resin layer is a polymer obtained using as a monomer at least one selected from the group consisting of acrylic acid and methacrylic acid, and
The tensile elastic modulus of the foaming agent-containing resin layer is 100 MPa to 200 MPa.
Unfoamed sheet.
2. Item 2. The unfoamed sheet according to Item 1, wherein the foaming agent-containing resin layer is a single layer or a multilayer.
3. Item 3. The unfoamed sheet according to Item 1 or 2, wherein the foaming agent-containing resin layer contains an inorganic compound.
4). The foaming decorative sheet obtained by heat-foaming the non-foamed sheet in any one of said items 1-3.
5). A method for producing a foamed decorative sheet comprising the following steps (i) to (ii):
(I) An unfoamed sheet is obtained by laminating at least a foaming agent-containing resin layer containing a polymer obtained by using at least one selected from the group consisting of acrylic acid and methacrylic acid as a monomer on the substrate. Forming step,
(Ii) A step of heating and foaming the unfoamed sheet when the tensile elastic modulus of the foaming agent-containing resin layer is within a range of 100 MPa to 200 MPa.

Hereinafter, the unfoamed sheet of the present invention will be described in detail.
1. Unfoamed sheet
The material of the base material is not particularly limited as long as it has mechanical strength, heat resistance and the like suitable as a decorative sheet base material, and a fibrous sheet can be generally used.

  Specifically, among fiber sheets, flame retardant paper (pulp-based sheets treated with flame retardants such as guanidine sulfamate and guanidine phosphate); inorganic additives such as aluminum hydroxide and magnesium hydroxide Inorganic paper including; fine paper; thin paper and the like.

Although the basis weight of the substrate is not critical, preferably about 50 to 300 g / ^{m 2,} about 50 to 80 g / ^{m 2} is more preferable.

The foaming agent-containing resin layer The foaming agent-containing resin layer contains, as a resin component, a polymer obtained by using at least one of acrylic acid (CH ₂ = CHCOOH) and methacrylic acid (CH ₂ = C (CH ₃ ) COOH) as a monomer. It is a layer formed by the resin composition.

Examples of the polymer (the polymer of the present invention) obtained using at least one of acrylic acid (CH ₂ ═CHCOOH) and methacrylic acid (CH ₂ ═C (CH ₃ ) COOH) as a monomer include, for example, at least acrylic acid and methacrylic acid. A copolymer obtained by combining one type of monomer and ethylene can be preferably used. More specifically, it is preferable to use at least one of ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer (EAA), and ionomer resin.

The content of acrylic acid or methacrylic acid in the copolymer is preferably about 4 to 20% by weight.
A commercial item can also be used regarding such resin.

  When the foaming agent-containing resin layer has a tensile elastic modulus of 100 MPa to 200 MPa, it is possible to improve the scratch resistance of a foamed sheet obtained by foaming an unfoamed sheet and achieve a desired foaming ratio. A more preferable tensile elastic modulus is 120 to 180 MPa.

  In addition, the tensile elasticity modulus in this specification is a value measured according to the prescription | regulation of JISK6734 "Plastic-Hard polyvinyl chloride sheet-Size and characteristic-Part 2: Sheet | seat less than 1 mm in thickness."

  Further, the melt flow rate value (JIS K7210: 190 ° C., 2.16 kg) of the resin component is usually about 1 to 500 g / 10 minutes depending on the type of polymer used, the molding method of the foaming agent-containing resin layer, and the like. It is preferable to set it as 5 to 150 g / 10 minutes.

  The content of the polymer of the present invention in the resin composition is not limited, but it is usually preferable to set appropriately within the range of 80 to 100% by weight.

  Although a foaming agent is not specifically limited, A thermal decomposition type foaming agent can be used conveniently. The pyrolytic foaming agent can be selected from known foaming agents. Examples include azo series such as azodicarbonamide (ADCA) and azobisformamide; hydrazide series such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. The content of the pyrolytic foaming agent can be appropriately set according to the type of foaming agent, the foaming ratio (the thickness of the foamed resin layer relative to the thickness of the foaming agent-containing resin layer), and the like. The expansion ratio is preferably 4 times or more. From this viewpoint, the content of the pyrolytic foaming agent is preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the resin component.

  If necessary, a foaming aid that accelerates the decomposition of the foaming agent can be used in combination in order to obtain a further foaming effect. The foaming aid varies depending on the type of foaming agent used.For example, when azodicarbonamide is used as the foaming agent, zinc oxide, lead sulfate, zinc stearate and other metal salts such as zinc oxide, lead sulfate and zinc stearate, adipic acid dihydrazide, Organic compounds such as urea are used. The content of the foaming aid is preferably about 0.3 to 10 parts by weight and more preferably about 1 to 8 parts by weight with respect to 100 parts by weight of the resin component.

  The resin composition may further contain an inorganic compound. As an inorganic compound, an inorganic filler, an inorganic pigment, etc. can be illustrated.

Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, molybdenum compound, barium sulfate, silica, talc, and clay. By including an inorganic filler, an effect of suppressing see-through, an effect of improving surface characteristics, and the like are obtained. Examples of inorganic pigments include titanium dioxide (TiO ₂ ), zinc white, carbon black, black iron oxide, yellow iron oxide, yellow lead, molybdate orange, cadmium yellow, nickel titanium yellow, chrome titanium yellow, iron oxide (valve Pattern), cadmium red, ultramarine blue, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, zinc sulfide and the like. Among the inorganic compounds, at least one selected from the group consisting of calcium carbonate and titanium dioxide is preferable. In addition, an inorganic compound can be used individually by 1 type or in mixture of 2 or more types.

  Although content of an inorganic compound is not limited, 0.1-200 weight part is preferable with respect to 100 weight part of resin components, and 1-100 weight part is more preferable.

  Various additives may be added to the resin composition. For example, organic pigments, cell regulators and the like. In addition, stabilizers, lubricants, and the like can be used as additives.

  Examples of organic pigments include aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, Organic pigments such as perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halogenated phthalocyanine). About 10-50 weight part is preferable with respect to 100 weight part of resin components, and, as for content of an organic pigment, about 15-30 weight part is more preferable.

  As the cell regulator, for example, a surfactant such as sodium fatty acid can be appropriately used.

  Although the thickness of a foaming agent containing resin layer is not limited, Usually, it is preferable to set it as about 40-100 micrometers.

Non-foamed resin layer B
In the present invention, a non-foamed resin layer (non-foamed resin layer B) may be formed between the base material and the foaming agent-containing resin layer as necessary. In particular, when the non-foamed resin layer B is formed as an adhesive layer, excellent adhesion between the base material and the foamed resin layer can be obtained in the foamed decorative sheet after foaming.

  The non-foamed resin layer B is not particularly limited. For example, polyethylene resin (PE), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methacrylic acid copolymer A coalescence (EMAA), an ethylene-acrylic acid copolymer (EAA), etc. can be used conveniently.

  The non-foamed resin layer B may contain known additives in addition to the resin component, but is preferably blended so that the content of the resin component is 70 to 100% by weight.

  The thickness of the non-foamed resin layer B is not limited, but is preferably about 3 to 50 μm, more preferably about 5 to 20 μm.

  Examples of the resin component constituting the adhesive layer include EVA, EMMA, ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), and the like.

Non-foamed resin layer A
A non-foamed resin layer A may be further formed on the front surface of the foaming agent-containing resin layer.

The non-foamed resin layer (non-foamed resin layer A) mainly protects the foamed resin layer in the foamed decorative sheet after foaming. In the present invention, although not particularly limited, polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer, and the like can be used. In particular, a layer formed of a resin composition containing, as a resin component, a polymer obtained by using at least one of acrylic acid (CH ₂ ═CHCOOH) and methacrylic acid (CH ₂ ═C (CH ₃ ) COOH) as a monomer is not used. A foamed resin layer is preferred.

  As the resin component, for example, a copolymer obtained by a combination of at least one monomer of acrylic acid and methacrylic acid and ethylene can be suitably used as the resin component. More specifically, it is desirable to use at least one of an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, and an ionomer resin. As the ionomer resin, a resin having a structure in which the molecules of ethylene-methacrylic acid copolymer and / or ethylene-acrylic acid copolymer are intermolecularly bonded with metal ions such as sodium and zinc can be used. When such a resin component is used, it is possible to form a strong layer particularly due to hydrogen bonds in the resin, so that excellent scratch resistance, abrasion resistance, and the like can be obtained. These may be known or commercially available.

  The content of acrylic acid or methacrylic acid in the copolymer is preferably about 4 to 15% by weight. Such a resin can also use a commercial item. A known additive can also be blended in the resin composition.

  The thickness of the non-foamed resin layer is not limited, but is preferably about 3 to 50 μm, more preferably about 5 to 20 μm.

  Moreover, although content of the said resin component in a resin composition is not limited, Usually, it is preferable to set suitably in the range of 70 to 100 weight%.

Pattern Pattern Layer In the present invention, a pattern pattern layer may be provided on the front surface of the non-foamed resin layer A as necessary.

  The design pattern layer imparts design properties to the foamed decorative sheet. Examples of the pattern include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern. A design pattern can be selected according to the kind of foaming decorative sheet.

  The pattern pattern layer can be formed, for example, by printing a pattern pattern on the front surface of the non-foamed resin layer A. In addition, when forming a picture pattern layer, you may form a primer layer previously as needed. Examples of printing methods include gravure printing, flexographic printing, silk screen printing, and offset printing. As the printing ink, a printing ink containing a colorant, a binder resin, and a solvent (or a dispersion medium) can be used. These inks may be known or commercially available.

  As the colorant, for example, a pigment used in the above-described foaming agent-containing resin layer can be appropriately used.

  The binder resin is, for example, an acrylic resin, a styrene resin, a polyester resin, a urethane resin, a chlorinated polyolefin resin, a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, an alkyd resin, or a petroleum resin. Examples include resins, ketone resins, epoxy resins, melamine resins, fluorine resins, silicone resins, fiber derivatives, rubber resins, and the like.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene Chlorinated organic solvents; and water.

  The thickness of the design pattern layer is different from the type of design pattern, but is generally preferably about 0.1 to 10 μm.

Surface protective layer (overcoat layer)
In the present invention, a surface protective layer may be provided on the surface of the design pattern layer for the purpose of adjusting the gloss and / or protecting the design pattern layer. The type of the surface protective layer is not limited, but an acrylic resin, a urethane resin, or the like is desirable. If it is a surface protective layer aiming at gloss adjustment, there exists a surface protective layer containing known fillers, such as a silica, for example. As a method for forming the surface protective layer, a known method such as gravure printing can be employed. In addition, when the adhesiveness of a pattern pattern layer and a surface protective layer is not fully acquired, a surface protective layer can also be provided after carrying out the adhesion process (primer process) of the surface of a pattern pattern layer.

  When forming a surface protective layer for the purpose of surface strength (scratch resistance, etc.), stain resistance, and protection of a pattern layer of a foamed decorative sheet, those containing an ionizing radiation curable resin as a resin component are suitable. It is. The ionizing radiation curable resin is preferably one that undergoes radical polymerization (curing) by electron beam irradiation.

  The thickness of the surface protective layer is not limited, but is preferably about 0.1 to 15 μm.

2. The manufacturing method of a foaming decorative sheet The manufacturing method of the foaming decorative sheet of this invention is the process of the following (i)-(ii):
(I) a foaming agent-containing resin layer comprising a polymer obtained by using at least one selected from the group consisting of acrylic acid and methacrylic acid as a monomer on a substrate; and
Obtaining an unfoamed sheet comprising a foaming agent-containing resin layer having a tensile modulus of 100 MPa to 200 MPa;
(Ii) A step of heating and foaming the unfoamed sheet obtained in the step (i).
including.

  Hereinafter, the manufacturing method of the foaming decorative sheet of this invention is demonstrated concretely.

(I) Forming an unfoamed sheet In the step (i), an unfoamed sheet is formed. The method for producing the unfoamed sheet is not particularly limited. For example, each material is melt-kneaded with a known kneader such as a Banbury mixer, pressure kneader, roll, single-screw extruder, twin-screw extruder, etc. It is obtained by laminating a foaming agent-containing resin layer on a base material after making it into a sheet with a known sheet molding machine such as a T-die. Moreover, you may laminate | stack a non-foaming resin layer on the upper and lower sides of the foaming agent containing resin layer as needed, or one side.

(Ii) In the step (ii) of heating and foaming an unfoamed sheet, the unfoamed sheet is heated and foamed when a tensile elastic modulus of the foaming agent-containing resin layer is in a range of 100 MPa to 200 MPa. Examples of the method for bringing the tensile modulus of the contained resin layer into the range of 100 MPa to 200 MPa include adjusting the storage environment (for example, temperature, humidity, etc.), the storage schedule, and the like as appropriate. In particular, since the foaming agent-containing resin layer described above contains a carboxyl group in the polymer molecule, it is understood that the tensile elastic modulus can be easily controlled depending on temperature, humidity conditions, and the like. In addition, when the tensile elasticity modulus of the foaming agent containing resin layer immediately after forming an unfoamed sheet is already in the range of 100 MPa to 200 MPa, the above-described adjustment may not be performed.

  The environment for storing the unfoamed sheet is appropriately adjusted, and the foaming agent-containing resin layer is heated when the tensile modulus of the foaming agent-containing resin layer is in the range of 100 MPa to 200 MPa (more preferably, 120 to 180 MPa). By doing so, a foamed resin layer is formed. The heating conditions are not limited as long as the foamed resin layer is formed by the decomposition of the pyrolytic foaming agent. The heating temperature is about 200 to 220 ° C., and the heating time is about 30 to 45 seconds.

  Electron beam irradiation may be performed before the heat treatment. Thereby, since a resin component can be bridge | crosslinked, the surface strength of a foaming decorative sheet, a foaming degree, etc. can be controlled. The energy of the electron beam is preferably about 150 to 250 kV. The irradiation amount is preferably about 1 to 7 Mrad. A known electron beam irradiation apparatus can be used as the electron beam source. Crosslinking can also be performed using a chemical crosslinking agent (also referred to as a crosslinking agent or a crosslinking aid).

  In the case of performing electron beam irradiation, the composition may contain a crosslinking agent. Any crosslinking agent that promotes crosslinking by electron beam irradiation may be used. Examples thereof include polyfunctional monomers such as neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate, oligomers, and the like. The crosslinking agent is preferably about 0 to 10 parts by weight, more preferably 1 to 4 parts by weight, based on 100 parts by weight of the resin component.

  When a surface protective layer containing an ionizing radiation curable resin is formed, the surface protective layer can be cured by electron beam irradiation. Such electron beam irradiation can be performed simultaneously (same processing) as electron beam irradiation performed to crosslink the resin contained in the foaming agent-containing resin layer. That is, after forming a foaming agent-containing resin layer, a non-foaming resin layer, a pattern layer, and a surface protective layer containing an ionizing radiation curable resin in this order, the resin contained in the foaming agent-containing resin layer is irradiated with an electron beam. The resin contained in the surface protective layer can be cured while being crosslinked.

  When producing a foam decorative sheet having a pattern layer, it is preferable to form the pattern layer on the surface of the non-foamed resin layer before the heat treatment. The pattern pattern layer may be formed as described above.

  The unfoamed sheet of the present invention is foamed when the tensile elastic modulus of the foaming agent-containing resin layer is within a specific range. Therefore, the foamed decorative sheet obtained by foaming the unfoamed sheet can achieve excellent surface strength and a desired expansion ratio.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Example 1
(1) Production of foamed decorative sheet A foaming agent-containing resin composition was melt-molded at 120 ° C with the following composition, then formed into a film having a thickness of 100 µm, and attached to the backing paper. Combined.
Foaming agent-containing resin composition:
Resin EMAA “Nuclelic N035C (methacrylic acid content (MAA) = 10% by weight, melt flow rate (MFR) = 35)), Mitsui DuPont Polychemical” 70 parts by weight Resin EMAA “Nucleel N1050H (MAA = 10% by weight) , MFR = 500), Mitsui DuPont Polychemical "30 parts by weight Titanium Dioxide" R-350, DuPont "20 parts by weight Calcium Carbonate" Whiteon H, Toyo Fine Chemical "40 parts by weight Foaming agent Azodicarbonamide" Uniform " AZ Ultra 3050I, Otsuka Chemical Co., Ltd. ”4.5 parts by weight foaming aid Adipic acid dihydrazide“ ADHS, Otsuka Chemical Co., Ltd. ”3 parts by weight Olefin oligomer“ DM01, Mitsui Chemicals Co., Ltd. ”2.5 parts by weight Let the resin composition be resin composition [1].
After the resin sheet bonded to the backing paper is stored for one day in an environment of 40 ° C. and 90% RH, the resin surface is irradiated with an electron beam (200 kV 50 kGy) to crosslink the resin, and then a foamed resin. The pattern was printed on the top by a gravure printing machine and heated in a foaming furnace to foam the foaming agent contained in the foaming agent-containing resin layer.
Furthermore, the above-mentioned foam was embossed with a textured pattern to obtain a desired foamed decorative sheet.

(2) Production of Resin Sheet Separately from the foamed decorative sheet produced in (1), the resin composition [1] is formed without being bonded to the backing paper, and is one day in an environment of 40 ° C. and 90% RH. After storage, an electron beam (200 kV 50 kGy) was irradiated to crosslink the resin to obtain a resin sheet.

Example 2
(1) A foamed decorative sheet, except that the storage environment and the number of storage days were set to 20 ° C./60% RH and 7 days instead of storage at 40 ° C./90% RH for 1 day, And (2) A resin sheet was obtained.

Example 3
(1) Foamed decorative sheet, as in Example 1, except that the storage environment and the number of storage days were 40 ° C./90% RH, instead of storage for 1 day, 40 ° C./20% RH, 7 days And (2) A resin sheet was obtained.

Example 4
(1) Foamed decorative sheet, as in Example 1, except that the storage environment and the number of storage days were 40 ° C./90% RH, instead of storage for 1 day, 40 ° C./90% RH, 7 days And (2) A resin sheet was obtained.

Example 5
The storage environment and the number of storage days are 40 ° C./90% RH for 1 day instead of 40 ° C./90% RH for 90 days, then 60 ° C./20% RH for 1 day, and then 40 ° C./90° Except for% RH and 1 day, (1) a foam decorative sheet and (2) a resin sheet were obtained in the same manner as in Example 1.

Example 6
(1) Production of foamed decorative sheet A foaming agent-containing resin composition was melt-molded at 120 ° C with the following composition, then formed into a film having a thickness of 100 µm, and attached to the backing paper. Combined.
Foaming agent-containing resin composition:
Resin EMAA “Nucleel N0908C (MAA = 9 wt%, MFR = 8), made by Mitsui DuPont Polychemical” 90 parts by weight modifier Hydrogenated petroleum resin “Alcon P-100, made by Arakawa Chemical” 10 parts by weight titanium dioxide “ R-350, made by DuPont ”20 parts by weight calcium carbonate“ Whiteon H, made by Toyo Fine Chemical ”40 parts by weight blowing agent Azodicarbonamide“ Uniform AZ Ultra 3050I, made by Otsuka Chemical ”4.5 parts by weight foaming aid adipic acid dihydrazide “ADHS, manufactured by Otsuka Chemical Co., Ltd.” 3 parts by weight Dispersant Olefin oligomer “DM01, manufactured by Mitsui Chemicals Co., Ltd.” 2.5 parts by weight The above-mentioned foaming agent-containing resin composition is referred to as resin composition [2].
The resin sheet bonded to the backing paper is not stored, and the resin is crosslinked without irradiating the resin surface with an electron beam. After that, the pattern is printed on the foamed resin by a gravure printing machine and heated in a foaming furnace. The foaming agent contained in the foaming agent-containing resin layer was foamed. Furthermore, the above-mentioned foam was embossed with a textured pattern to obtain a desired foamed decorative sheet.

(2) Production of resin sheet Separately from the foamed decorative sheet produced in (1), the resin composition [2] is formed without being bonded to the backing paper, and then stored without being subjected to electron beam irradiation. Without obtaining a resin sheet.

Example 7
(1) Production of foamed decorative sheet A foaming agent-containing resin composition was melt-molded at 120 ° C with the following composition, then formed into a film having a thickness of 100 µm, and attached to the backing paper. Combined.
Foaming agent-containing resin composition:
Resin EMAA “Nucleel N1560 (MAA = 15 wt%, MFR = 60), manufactured by Mitsui DuPont Polychemical” 100 parts by weight Titanium dioxide “R-350, manufactured by DuPont” 20 parts by weight Calcium carbonate “Whiteon H, manufactured by Toyo Fine Chemical 40 parts by weight blowing agent Azodicarbonamide “Uniform AZ Ultra 3050I, manufactured by Otsuka Chemical” 4.5 parts by weight foaming aid Adipic acid dihydrazide “ADHS, manufactured by Otsuka Chemical” 3 parts by weight Olefin oligomer “DM01, manufactured by Mitsui Chemicals” 2.5 parts by weight In addition, let the said foaming agent containing resin composition be resin composition [3].
Without storing the resin sheet bonded to the backing paper, the resin surface was irradiated with an electron beam (200 kV 50 kGy) to crosslink the resin, and then printed on a foamed resin by a gravure printer, The foaming agent contained in the foaming agent-containing resin layer was foamed by heating. Furthermore, the above-mentioned foam was embossed with a textured pattern to obtain a desired foamed decorative sheet.

(2) Production of Resin Sheet Separately from the foamed decorative sheet produced in (1), the resin composition [3] is formed without being bonded to the backing paper, and then not stored, and the electron beam (200 kV 50 kGy) Was irradiated to crosslink the resin to obtain a resin sheet.

Comparative Example 1
(1) Foamed decorative sheet and (2) Resin in the same manner as in Example 1 except that the storage environment and the storage days were changed to 40 ° C./90% RH, 1 day storage, but no storage (not stored) A sheet was obtained.

Comparative Example 2
(1) A foamed decorative sheet, except that the storage environment and the storage days were 40 ° C./90% RH, 40 days / 90% RH, 90 days instead of 40 days / 90% RH, And (2) A resin sheet was obtained.

Comparative Example 3
(1) Foamed decorative sheet, except that the storage environment and the storage days were 40 ° C./90% RH, 1 day instead of 40 ° C./90% RH, 180 days And (2) A resin sheet was obtained.

Comparative Example 4
(1) Foamed decorative sheet, as in Example 1, except that the storage environment and the number of storage days were changed to 40 ° C./90% RH for 1 day and 5 ° C./15% RH for 7 days, And (2) A resin sheet was obtained.

Comparative Example 5
(1) Foamed decorative sheet and (2) Resin in the same manner as in Example 6 except that the storage environment and the number of storage days were set to 40 ° C./90% RH and 3 days instead of no storage (not stored). A sheet was obtained.

Comparative Example 6
(1) Foamed decorative sheet and (2) Resin in the same manner as in Example 7 except that the storage environment and the number of storage days were changed to 40 ° C./90% RH and 3 days instead of no storage (not stored) A sheet was obtained.

Comparative Example 7
(1) Production of foamed decorative sheet A foaming agent-containing resin composition was melt-molded at 120 ° C with the following composition, then formed into a film having a thickness of 100 µm, and attached to the backing paper. Combined.
Foaming agent-containing resin composition:
Resin EVA “Evaflex V406 (vinyl acetate content (VA) = 20 wt%, MFR = 20), made by Mitsui DuPont Polychemical” 90 parts by weight modifier Hydrogenated petroleum resin “Alcon P-100, made by Arakawa Chemical "10 parts by weight titanium dioxide" CR-60-2, manufactured by Ishihara Sangyo "20 parts by weight blowing agent azodicarbonamide" Uniform AZ Ultra 3050I, manufactured by Otsuka Chemical "3.5 parts by weight foaming aid" OF-101, manufactured by ADEKA "5 parts by weight dispersant" MFX-50J, manufactured by Daikyo Kasei Co., Ltd. "3 parts by weight crosslinking aid" JUA-702, manufactured by JSR "1 part by weight The above-mentioned foaming agent-containing resin composition is the resin composition [4] .
After the resin sheet bonded to the backing paper is stored for one day in an environment of 40 ° C. and 90% RH, the resin surface is irradiated with an electron beam (200 kV 30 kGy) to crosslink the resin, and then a foamed resin. The pattern was printed on the top by a gravure printing machine and heated in a foaming furnace to foam the foaming agent contained in the foaming agent-containing resin layer. Furthermore, the above-mentioned foam was embossed with a textured pattern to obtain a desired foamed decorative sheet.

(2) Preparation of resin sheet Separately from the foamed decorative sheet prepared in (1), the resin composition [4] is formed without being bonded to the backing paper, and is subjected to an environment of 40 ° C. and 90% RH for one day. After storage, an electron beam (200 kV 30 kGy) was irradiated to crosslink the resin to obtain a resin sheet.

Comparative Example 8
(1) Foamed decorative sheet, except that the storage environment and the storage days were 40 ° C./90% RH, 7 days instead of 40 ° C./90% RH, 7 days (1) And (2) A resin sheet was obtained.

Comparative Example 9
(1) Foamed decorative sheet, in the same manner as in Comparative Example 7, except that the storage environment and the storage days were 40 ° C./90% RH, instead of storage for 1 day, 40 ° C./90% RH, 90 days And (2) A resin sheet was obtained.

Comparative Example 10
(1) Foamed decorative sheet, in the same manner as in Comparative Example 7, except that the storage environment and the storage days were changed to 40 ° C./90% RH, 1 day storage, 5 ° C./15% RH, 7 days And (2) A resin sheet was obtained.

Comparative Example 11
(1) Production of foamed decorative sheet A foaming agent-containing resin composition was melt-molded at 120 ° C with the following composition, then formed into a film having a thickness of 100 µm, and attached to the backing paper. Combined.
Foaming agent-containing resin composition:
Resin EVA “Evaflex P1007 (VA = 10 wt%, MFR = 9), 95 parts by weight from Mitsui DuPont Polychemical” modifier Hydrogenated petroleum resin “Alcon P-100, made by Arakawa Chemical” 5 parts by weight titanium dioxide "CR-60-2, manufactured by Ishihara Sangyo" 20 parts by weight foaming agent Azodicarbonamide "Uniform AZ Ultra 3050I, manufactured by Otsuka Chemical" 3.5 parts by weight foaming aid "OF-101, manufactured by ADEKA" 5 parts by weight dispersant " MFX-50J, manufactured by Daikyo Kasei Co., Ltd. ”3 parts by weight crosslinking aid“ JUA-702, manufactured by JSR ”1 part by weight The above-mentioned foaming agent-containing resin composition is referred to as resin composition [5].
The resin sheet bonded to the backing paper is not stored, and the resin surface is irradiated with an electron beam (200 kV 30 kGy) to crosslink the resin, and then printed on a foamed resin by a gravure printing machine, and foamed. The foaming agent contained in the foaming agent-containing resin layer was foamed by heating in a furnace. Furthermore, the above-mentioned foam was embossed with a textured pattern to obtain a desired foamed decorative sheet.

(2) Preparation of resin sheet Separately from the foamed decorative sheet prepared in (1), the resin composition [5] was formed without being bonded to the backing paper, stored, and irradiated with an electron beam (200 kV 30 kGy). Then, the resin was crosslinked to obtain a resin sheet.

Comparative Example 12
(1) Foamed decorative sheet and (2) Resin in the same manner as in Comparative Example 11 except that the storage environment and the number of storage days were set to 40 ° C./90% RH and 7 days instead of no storage (not stored). A sheet was obtained.

Test Example 1: Scratch resistance test The scratch resistance test was performed on the foamed decorative sheets produced in Examples 1 to 7 and Comparative Examples 1 to 12 (1). Attach a test piece to the Gakushin Abrasion Tester (JIS L0849 Abrasion Tester Type II), use a metal nail specified by the same group for the tester's friction element, apply a load of 500g to the tip of the metal nail, The surface condition after the test of the test piece was observed by making five reciprocations, and judged by the degree of surface breakage. The evaluation methods were as follows: ○: no tearing, x: tearing.

Test Example 2: Foam volume test The foam volume of the foamed decorative sheets produced in Examples 1 to 7 and Comparative Examples 1 to 12 (1) was measured by the thickness ratio (magnification) before and after foaming. In addition, the evaluation method relates to the thickness ratio (magnification) before and after foaming.
○: 4 times or more, x: less than 4 times.

Test Example 3: Measurement of tensile elastic modulus of unfoamed resin sheet The tensile elastic modulus test was evaluated according to the plastic tensile test method of JIS-K-7113. A test piece shall be based on the test piece in JIS-K-7113, and the tensile modulus is the Instron 5500 obtained from the obtained test pieces (resin sheets obtained in Examples 1 to 7 and Comparative Examples 1 to 12). Obtained by measuring with a mold material testing machine. The measurement was performed at a distance between marked lines of 25 mm, a tensile speed of 10 mm / min, an average value of five measurements, a measurement temperature of 23 ± 2 ° C., and a relative humidity of 50 ± 5%.

  Table 1 shows the results of the above-described Test Examples 1 to 3.

Claims (5)

An unfoamed sheet obtained by laminating a foaming agent-containing resin layer on a substrate,
The resin component of the foaming agent-containing resin layer is a polymer obtained using as a monomer at least one selected from the group consisting of acrylic acid and methacrylic acid, and
The tensile elastic modulus of the foaming agent-containing resin layer is 100 MPa to 200 MPa.
Unfoamed sheet. The unfoamed sheet according to claim 1, wherein the foaming agent-containing resin layer is a single layer or a multilayer. The unfoamed sheet according to claim 1 or 2, wherein the foaming agent-containing resin layer contains an inorganic compound. The foaming decorative sheet obtained by heat-foaming the unfoamed sheet in any one of Claims 1-3. A method for producing a foamed decorative sheet comprising the following steps (i) to (ii):
(I) An unfoamed sheet is obtained by laminating at least a foaming agent-containing resin layer containing a polymer obtained by using at least one selected from the group consisting of acrylic acid and methacrylic acid as a monomer on the substrate. Forming step,
(Ii) A step of heating and foaming the unfoamed sheet when the tensile elastic modulus of the foaming agent-containing resin layer is within a range of 100 MPa to 200 MPa.